/** @file ../include/ctype.h

   @internalComponent

*/

 /** @fn  isalnum(int c)

@param c

@return   The isalnum function returns zero if the character is not alphanumeric and

returns non-zero if the character tests true.

The function isalnum returns non-zero if 'c' is alphanumeric i.e. it belongs to class alnum(see defns for definition). In other words, it returns non-zero if the test for isalpha or isdigit is non-zero, irrespective of the program's current locale. For single character representations,

the value of the argument is

representable as an unsigned char

or the value of EOF.

 The functionality of this API is independent of the program's current locale and so it returns non-zero for all the characters (of various locales supported) that belong to the class alnum,

irrespective of the locale they belong to.

Examples:

@code

#include<ctype.h> //isalnum()

#include<stdio.h> //printf()

void test_isalnum()

{

   int arr[]={'8',0xe1,'5','Z',0xfd};

   int i = 0;

   int size = 5;

   for( i=0; i<size; i++)

   {

      int ret = isalnum(arr[i]); //call to the API with chars in arr[]

      if( (!ret) != 0 )

      {

          printf("

%c is not alphanumeric", arr[i]);

      }

      else

      {

          printf("

%c is an alphanumeric ", arr[i]);

      }

   }

   printf("

");

}

@endcode

 Output

@code

a is an alphanumeric

á is an alphanumeric

5 is an alphanumeric

Z is an alphanumeric

ý is an alphanumeric

@endcode

@see isalpha()

@see isdigit()

@see iswalnum()

 @publishedAll

 @externallyDefinedApi

 */

 /** @fn  isalpha(int c)

@param c

@return   The isalpha function returns non-zero if the character is an alphabet and zero otherwise.

  The isalpha function returns non-zero if 'c' is an alphabet i.e. it belongs to class alpha (see defns for definition). In other words, it returns non-zero if the test for isupper or islower is non-zero,irrespective of the program's current locale. The function will return non-zero for also those characters that are alphabets and cannot be categorised as upper or lower case.

For single character representations,

the value of the argument is

representable as an unsigned char

or the value of EOF.

 The functionality of this API is independent of the program's current locale and so it returns non-zero for all the characters (of various locales supported) that belong to the class alpha, irrespective of the locale they belong to.

Examples:

@code

#include<ctype.h> //isalpha()

#include<stdio.h> //printf()

void test_isalpha()

{

   int arr[]={'a',0xe1,'5','Z',0xfd};

   int i = 0;

   int size = 5;

   for( i=0; i<size; i++)

   {

      int ret = isalpha(arr[i]); //call to the API with chars in arr[]

      if( (!ret) != 0 )

      {

        printf("

%c is not an alphabet", arr[i]);

      }

      else

      {

        printf("

%c is an alphabet", arr[i]);

      }

   }

   printf("

");

}

@endcode

 Output

@code

a is an alphabet

á is an alphabet

5 is not an alphabet

Z is an alphabet

ý is an alphabet

@endcode

@see islower()

@see isupper()

@see iswalpha()

 @publishedAll

 @externallyDefinedApi

 */

 /** @fn  iscntrl(int c)

@param c

@return   The iscntrl function returns non-zero if 'c' is control character and zero otherwise.

  The iscntrl function tests if 'c' is a control character i.e. it belongs to class cntrl(see defns for definition).

For single character representations,

the value of the argument is

representable as an unsigned char

or the value of EOF.

 The functionality of this API is independent of the program's current locale and so it returns non-zero for all the characters (of various locales supported) that belong to the class cntrl, irrespective of the locale they belong to.

Examples:

@code

#include<ctype.h> //iscntrl()

#include<stdio.h> //printf()

int test_iscntrl()

{

   int arr[]={0x7F,’9’,’A’,’$’,’\a’ };

   int i = 0;

   int size = 5;

   for( i=0; i<size; i++)

   {

      int ret = iscntrl(arr[i]); //call to the API with chars in arr[]

      if( (!ret) != 0 )

      {

         printf("

%c is not cntrl char ", arr[i]);

      }

      else

      {

         printf("

%c is cntrl char", arr[i]);

      }

   }

printf("

");

}

@endcode

 Output

@code

 is cntrl char

9 is not cntrl char

A is not cntrl char

$ is not cntrl char

 is cntrl char

@endcode

@see iswcntrl()

 @publishedAll

 @externallyDefinedApi

 */

 /** @fn  isdigit(int c)

@param c

@return   The isdigit function returns non-zero if the character is a digit and zero otherwise.

The isdigit function tests if ’c’ is a decimal digit character. Regardless of locale, this includes the following characters only: 

@code

‘‘0’’  ‘‘1’’   ‘‘2’’   ‘‘3’’   ‘‘4’’ 

‘‘5’’ ‘‘6’’   ‘‘7’’   ‘‘8’’   ‘‘9’’ 

@endcode

Examples:

@code

#include<ctype.h> //isdigit()

#include<stdio.h> //printf()

void test_isdigit()

{

   int arr[]={'8',0xe1,'5','Z',0xfd};

   int i = 0;

   int size = 5;

   for( i=0; i<size; i++)

   {

     int ret = isdigit(arr[i]); //call to the API with chars in arr[]

     if( (!ret) != 0 )

     {

         printf("

%c is not a digit", arr[i]);

     }

     else

     {

         printf("

%c is a digit", arr[i]);

     }

     }

printf("

");

}

@endcode

 Output

@code

8 is a digit

á is not a digit

5 is a digit

Z is not a digit

ý is not a digit

@endcode

@see iswdigit()

@see defns()

 @publishedAll

 @externallyDefinedApi

 */

 /** @fn  isgraph(int c)

@param c

@return   The isgraph function returns non-zero if 'c' has a visible representation and zero otherwise.

  The isgraph function returns non-zero if 'c' has visible representation i.e. it belongs to class graph(see defns for definition). It does not consider characters classified under class space

and class cntrl (see defns for definition).

For single character representations,

the value of the argument is

representable as an unsigned char

or the value of EOF.

 The functionality of this API is independent of the program's current locale and so it returns non-zero for all the characters (of various locales supported) that belong to the class graph, irrespective of the locale they belong to.

Examples:

@code

#include<ctype.h> //isgraph()

#include<stdio.h> //printf()

int test_isgraph()

{

   int arr[]={’n’,’\f’, ’6’, ’ ’};

   int i = 0;

   int size = 4;

   for( i=0; i<size; i++)

   {

     int ret = isgraph(arr[i]); //call to API with chars in arr[]

     if( (!ret) != 0 )

     {

        printf("

%c is not visible char ", arr[i]);

     }

     else

     {

        printf("

%c is visible char", arr[i]);

     }

   }

printf("

");

}

@endcode

 Output

@code

n is  visible char

is not visible char

6 is visible char

 is not visible char

@endcode

@see iswgraph()

 @publishedAll

 @externallyDefinedApi

 */

 /** @fn  islower(int c)

@param c

@return   The islower function returns non-zero is 'c' is a lower-case alphabet and zero otherwise.

  The islower function tests if 'c' belongs to the set of lower-case letters i.e. it belongs to class lower(see defns for definition).

For single character representations,

the value of the argument is

representable as an unsigned char

or the value of EOF.

 The functionality of this API is independent of the program's current locale and so it returns non-zero for all the characters (of various locales supported) that belong to the class lower, irrespective of the locale they belong to.

Examples:

@code

#include<ctype.h> //islower()

#include<stdio.h> //printf()

int test_islower()

{

  int arr[]={0x0126,0xee,'r','9','g'};

  int i = 0;

  int size = 5;

  for( i=0; i<size; i++)

  {

     int ret = islower(arr[i]); //call to the API with chars in the arr[]

     if( (!ret) != 0 )

     {

         printf("

%c is not in lower-case ", arr[i]);

     }

     else

     {

         printf("

%c is in lower-case", arr[i]);

     }

  }

printf("

");

}

@endcode

 Output

@code

& is not in lower-case

î is in lower-case

r is in lower-case

9 is not in lower-case

g is in lower-case

@endcode

@see iswlower()

@see tolower()

 @publishedAll

 @externallyDefinedApi

 */

 /** @fn  isprint(int c)

@param c

@return   The isprint function returns non-zero if 'c' is printable and zero otherwise.

  The isprint function returns true if 'c' is a printable character. It considers characters under class space, but characters falling under class cntrl will not be considered(see defns for definition of these classes).

 For single character representations,

the value of the argument is

representable as an unsigned char

or the value of EOF.

 The functionality of this API is independent of the program's current locale and so it returns non-zero for all the characters (of various locales supported) that belong to the class print(see defns for definition), irrespective of the locale they belong to.

Examples:

@code

#include<ctype.h> //isprint()

#include<stdio.h> //printf()

int test_isprint()

{

   int arr[]={’n’,’\f’, 0xe1, ’6’, ’ ’};

   int i = 0;

   int size = 5;

   for( i=0; i<size; i++)

   {

      int ret = isprint(arr[i]); //call to the API with the chars in arr[]

      if( (!ret) != 0 )

      {

         printf("

%c is not printable char ", arr[i]);

      }

      else

      {

         printf("

%c is printable char", arr[i]);

      }

   }

printf("

");

}

@endcode

 Output

@code

n is printable char

  is not printable char

á is not printable char

6 is printable char

  is printable char

@endcode

@see iswprint()

 @publishedAll

 @externallyDefinedApi

 */

 /** @fn  ispunct(int c)

@param c

@return   The ispunct function returns non-zero if 'c' is a punctuation character and zero otherwise.

  The ispunct function tests if 'c' is a punctuation character i.e. it belongs to class punct(see defns for definition). Characters under class space

or a

character for which isalnum is true(non-zero) are excluded. In other words, it tests for punctuation characters.

For single character representations,

the value of the argument is

representable as an unsigned char

or the value of EOF.

 The functionality of this API is independent of the program's current locale and so it returns non-zero for all the characters (of various locales supported) that belong to the class punct, irrespective of the locale they belong to.

Examples:

@code

#include<ctype.h> //ispunct()

#include<stdio.h> //printf()

int test_ispunct()

{

  int arr[]={0x3003,'3',0x301C,'*', '+'};

  int i = 0;

  int size = 5;

  for( i=0; i<size; i++)

  {

     int ret = ispunct(arr[i]); //call to the API with chars in arr[]

     if( (!ret) != 0 )

     {

         printf("

0x%x is not a punc char ", arr[i]);

     }

     else

     {

         printf("

0x%x is a punc char", arr[i]);

     }

}

printf("

");

return 0;

}

@endcode

 Output

@code

0x3003 is a punc char

0x33 is not a punc char

0x301c is a punc char

0x2a is a punc char

0x2b is a punc char

@endcode

@see iswpunct()

 @publishedAll

 @externallyDefinedApi

 */

 /** @fn  isspace(int c)

@param c

@return   The isspace function returns non-zero if 'c' is space character and zero otherwise.

  The isspace function tests if 'c' is from among white-space characters i.e. it belongs to class space(see defns for definition).

This includes the following standard characters:

 SPACE

 FORM-FEED

 NEWLINE

 CARRIAGE-RETURN

 TAB

 VERTICAL-TAB

 For single character representations,

the value of the argument is

representable as an unsigned char

or the value of EOF.

 The functionality of this API is independent of the program's current locale and so it returns non-zero for all the characters (of various locales supported) that belong to the class space, irrespective of the locale they belong to.